/// <summary>
/// Game draw.
/// </summary>
/// <param name="gameTime"></param>
protected override void Draw(GameTime gameTime)
{
_renderContext.Attach();
_renderContext.Clear(Color.White);
base.Draw(gameTime);
_renderContext.Detach();
}
public void Draw(GameTime gameTime)
{
_renderContext.Clear(Color.White);
_renderContext.Attach();
_world.Draw(_renderContext, _camera, gameTime);
_renderContext.Detach();
}
protected override void Draw(GameTime gameTime)
{
base.Draw(gameTime);
// this demonstrates the 4 options we have of using ChangeRenderTarget
// 1. existing rendertarget = back buffer and we set a different rendertarget
GraphicsDevice.SetRenderTarget(null);
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("We set rendertarget to null, thus we should draw directly to back buffer");
}
// anything within the using will render to the rendertarget
using (_renderContext.RenderTo(_rt1, BackBufferSwapUsage.OriginalBehaviour))
{
if (GraphicsDevice.RenderTargetCount != 1)
{
throw new NotSupportedException("We set rendertarget, thus we should draw directly to it");
}
_renderContext.Clear(Color.Blue);
_renderContext.Attach();
// render a 3D cube that is rotating
var s = gameTime.GetTotalElapsedSeconds();
// cube is 10*10*10, center it so we rotate around its core
var world = Matrix.CreateTranslation(new Vector3(-5, -5, -5)) * Matrix.CreateRotationY(s) * Matrix.CreateRotationX(s);
var v = _camera.View;
var p = _camera.Projection;
_renderContext.DrawMesh(_mesh, world, v, p, new SolidColorBrush(Color.Green), new SolidColorPen(Color.Black));
_renderContext.Detach();
}
// now we render to the original backbuffer again because ChangeRenderTarget reset the state automatically
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("Rendertarget was set to null by Dispose of the using, thus we should draw directly to back buffer again");
}
// 2. existing rendertarget and we set a different one
GraphicsDevice.SetRenderTarget(_rt2);
using (_renderContext.RenderTo(_rt3, BackBufferSwapUsage.OriginalBehaviour))
{
// this should fill rt3 and not rt2
_renderContext.Clear(Color.Red);
}
// this should now fill rt2 and not rt3
GraphicsDevice.SetRenderTarget(_rt2);
_renderContext.Clear(Color.Green);
if (GraphicsDevice.RenderTargetCount != 1)
{
throw new NotSupportedException("Rendertarget was set to null by Dispose of the using, thus we should draw directly to back buffer again");
}
// 3. existing rendertarget and set to backbuffer
using (_renderContext.RenderTo(null, BackBufferSwapUsage.OriginalBehaviour))
{
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("Rendertarget was set to null by Dispose of the using, thus we should draw directly to back buffer again");
}
}
GraphicsDevice.SetRenderTarget(null);
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("Rendertarget was set to null, thus we should draw directly to back buffer again");
}
// 4. back buffer is set and we set to backbuffer
using (_renderContext.RenderTo(null, BackBufferSwapUsage.OriginalBehaviour))
{
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("Rendertarget was set to null by Dispose of the using, thus we should draw directly to back buffer again");
}
}
if (GraphicsDevice.RenderTargetCount > 0)
{
throw new NotSupportedException("Rendertarget was set to null by Dispose of the using, thus we should draw directly to back buffer again");
}
// now draw the actual rendertargets onto backbuffer
// clear with cornflower blue (visible only in the bottom right corner)
_renderContext.Clear(Color.CornflowerBlue);
_renderContext.Attach();
int w = GraphicsDevice.Viewport.Width;
int h = GraphicsDevice.Viewport.Height;
// top left rendertarget contains the rotating cube and has a blue background
_renderContext.DrawTexture(_rt1, new Rectangle(0, 0, w / 2, h / 2), Color.White);
// top right has the rendertarget we filled with green
_renderContext.DrawTexture(_rt2, new Rectangle(w / 2, 0, w / 2, h / 2), Color.White);
// bottom left contains the rendertarget we filled with red
_renderContext.DrawTexture(_rt3, new Rectangle(0, h / 2, w / 2, h / 2), Color.White);
var border = new Rectangle(w - 50, h - 50, 50, 50);
_renderContext.DrawTexture(_pixel, border, Color.Yellow);
var border2 = new Rectangle(w - 100, h - 100, 100, 50);
_renderContext.DrawTexture(_pixel, border2, Color.Red);
_renderContext.Detach();
}